Low Capacity Straight 6's

[welshpug 1,657]

Naah, 2.0 ew is more obvious

[Simes 248 2 Cars]

The early Triumph Vitesse had a 1.6 straight 6.

 

[24seven 104]

2.0 Duratec is the obvious choice, you don't need 6 cylinders.

 

Nor do I want just another 4 pot.

[Ryan 99]

What about an Audi 5-pot? Very torquey, and an interesting sound...

[welshpug 1,657]

cast iron aren't they...

 

Volvo 5 pot! alloy B5202/5204 are 2.0, Bore is 81 mm (3.2 in) and stroke is 77 mm (3.0 in).

 

 

 

they did do 6's but they're 2.9+

Edited August 31, 2012 by welshpug

[kyepan 291]

3 rotor wankel, very light, great sound when normally aspirated and rev to the moon when built to a high spec. Rare as unicorn tears though.

[jackherer 543]

hey did do 6's but they're 2.9+

 

Not that it helps in this case but my old S80 T6 was 'only' 2.8.

[Cameron 16]

Another vote for a 5-pot.. they sound awesome!

[24seven 104]

That they do. I'm a big fan of the sound of a straight 5, but I don't want one here.

[Cameron 16]

I still think a 6-pot is a terrible idea btw.. You should definitely be using a 4-pot for a Caterfield-type kit car. A 6-pot will put waaaaay too much weight up front.

[welshpug 1,657]

only if you don't build it right, i.e like an Audi

 

I was looking under the bonnet of a Z4 yesterday, the nose of the crank is just behind the front of the wheels, top of the struts around the 3rd cylinder, just make it longer

[Cameron 16]

Yeah but a Z4 is like 99% front end!

[MiniGibbo 142]

The longer the car the more boring too..

 

Who wants a car that rear end dosent try to overtake the front at the first sight of a bend

[rallyeash 155]

A tuned 4pot surely would be much better, yes a 6pot would be different and sound cool but just seems abit pointless

[24seven 104]

Yeah but a Z4 is like 99% front end!

 

And a caterfieldcost isn't?

 

A tuned 4pot surely would be much better, yes a 6pot would be different and sound cool but just seems abit pointless

 

Is it any more pointless than all of us lot bumming around in 20 year old French tin cans? Is it any more pointless than HRT turning up to every Grand Prix weekend knowing that they'll qualify last and finish last?

 

I fancy something different and I'm confident I can make it work well. It won't be a standard engine - far from it at the 9000-10000rpm I'd like to build it for. The chassis isn't going to be off the shelf or pre-designed either. If I were to use the basic Locost design, I'd tear it in half with the torque of the engine. It's going to be based on a Locost and then heavily reworked to fit the engine I want in the way I want, all because I can. This is all a few years off yet anyway, for all I know I may never bother to race it and just keep it for weekend A/B-road blasts when the sun comes out.

[welshpug 1,657]

perfectly reasonable argument

 

is the lower capacity specifically in the aim to make it rev?

[rallyeash 155]

I know what your saying but coupling a 6pot upto a running gear isn't going to be straight forward and tuning isn't going to be either, or you could have a common 4pot lump that has tuning parts readily available and can easily mix and match oem running gear to build the kit car.

 

In summary a 4pot 2l would be cheaper, easier and quicker...

Edited September 10, 2012 by rallyeash

[Cameron 16]

I totally understand your reasoning, it's just not the way I'd go about it.. but then a lot of people have said that to me too! Feel free to totally ignore my advice as I have theirs.

[Rippthrough 98]

There's nothing like the silky smoothness of a 6 pot no matter what size it is. And they can sound awesome with enough rpms.

[24seven 104]

perfectly reasonable argument

 

is the lower capacity specifically in the aim to make it rev?

 

Pretty much. The BMW engines are quite over-square as they are, and if I'm right in thinking I can use the shorter con rods from the 2.5 straight into the 2.0, then deck the block by the difference in piston height at TDC I could end up with a nice, revvy and short engine coupled with a dry sump to keep the centre of mass low as well. this is all "on paper" though. I might not be able to take that much off the block even if the rods will fit. It's just brainstorming at the moment.

 

I know what your saying but coupling a 6pot upto a running gear isn't going to be straight forward and tuning isn't going to be either, or you could have a common 4pot lump that has tuning parts readily available and can easily mix and match oem running gear to build the kit car.

 

In summary a 4pot 2l would be cheaper, easier and quicker...

 

OEM running gear is irrelevant unless I want to be lumped with old, heavy kit-car-common Ford stuff. This isn't supposed to be an off-the-shelf build.

 

 

I totally understand your reasoning, it's just not the way I'd go about it.. but then a lot of people have said that to me too! Feel free to totally ignore my advice as I have theirs.

 

haha, I was one of those people too, briefly.

[Tesstuff 222]

In summary a 4pot 2l would be cheaper, easier and quicker...

 

You wish - my 205 v6 was way cheaper than yours, maybe not easier, and is probably just as quick.

 

There's nothing like the silky smoothness of a 6 pot no matter what size it is. And they can sound awesome with enough rpms.

 

So true, sounds wonderful on cam and silky smooth.

[rallyeash 155]

Race for slips.....

 

:-P

[welshpug 1,657]

M52?

 

4.5mm is probably a hell of a deck, is it not better to use a longer rod to lower the side thrust forces and piston speeds?

[24seven 104]

M52?

 

4.5mm is probably a hell of a deck, is it not better to use a longer rod to lower the side thrust forces and piston speeds?

 

Yes, M52B20 with the rods from a B25. I'm thinking more to reduce the mass of the moving parts to help reach the RPM target I want than side thrust. It's not like I'd be using drastically shorter con rods, just the (presumably) shorter rods from the B25. Imagine using shorter XU9 con rods in an XU6 and decking the block/skimming the head to get the compression ratio back (I'm not saying it's doable on an XU, just making an analogy).

 

I realise now that I have my numbers completely mixed up, having originally assumed the 2.5 was just a longer stroke than the 2.0, so ignore the 4.5mm. I'll do more research nearer the time. The 2.0 engines go nice and cheap on eBay, especially the single vanos ones, presumably because everyone wants double vanos or the bigger engines. Whatever I get I'll be ditching any variable timing regardless.

[24seven 104]

Well, as with all ideas it seems, this one is already being done. I'm still going to build one regardless. ;p

Edited September 13, 2012 by 24seven